The Eye in the Sky

GPS Satellite

Has the GPS had its day? And even if good upkeep can maintain it, will a competing system soon take over? Drew Turney finds out.

“It’s an exquisite technology but it was designed in the time of record players and vacuum tubes and the design brief to the engineers was to track intercontinental ballistic missiles. They never imagined a world with iPads and mobile phones.”

That’s how positioning system entrepreneur Nunzio Gambale describes the global positioning system (GPS), and we’ll hear more from him later. Like the Internet, the GPS has morphed into something quite different from its original purpose, an enabler for other tools and industries to piggyback to make life better for everyone.

And it’s much more than just finding the address of a party late at night with your Tomtom or tagging iPhone photos with your location on Facebook. Driverless harvesters in vast farmlands sow thousands of square kilometres, patiently trundling up and down fields while GPS signals direct them with accuracy of around 10 centimetres.

Approved by the US Congress because of its defence utility, the GPS frequency band is divided into three segments — military use, commercial use (Control segment) and one for the rest of us with our satnavs and tablets(User segment).

Even though they have the capacity, the US military isn’t likely to shut the whole thing down in the event of a war like you’ve heard. It has its own very strong dedicated signal and as we’ll see, security concerns have been prompting official calls for an alternative for quite awhile.

Today, the reason your $100 GPS from Dick Smith or JB Hi-fi can direct you with such accuracy is because at midnight on May 1, 2000, Bill Clinton had the function of ‘selective availability’ switched off to widen the possibilities for civilian use. In the years prior, the general public signal was distorted to ensure accuracy of only about 100 metres instead of the handful of feet we know today.

Time for a change?

But as we know, the GPS has been up there a long time. Not that the machines that make up the constellation (the name given to the orbiting satellites) are still 70’s era technology — the most recent launch was in May this year, and the oldest serving satellite still in operation came online in December 1990. But it’s an old concept, and we live in a very different world.

Part of the problem is that we have to turn over the technology to keep up with the latest standards. But where it’s easy to throw out your 2G mobile for a touchscreen smartphone, replacing satellites isn’t cheap. “They’re living longer than they were designed to live,” says Andrew Dempster, director of the University of NSW’s Australian Centre for Space Engineering Research. “That’s not so good because the US has built a lot of new satellites that are better than the ones up there and they’re just sitting on the ground waiting for the ones in the sky to die so they can be launched. Because satellites are living so long the system isn’t as accurate as it might be.”

But the main problem with the GPS is simple physics. As we know every time we walk indoors, through a CBD surrounded by tall buildings or even a densely wooded park, the signal strength from 20,000km over our heads is very weak. It was fine for tracking missiles skimming the tropopause but we need direct line of sight to satellite navigation systems for a lot more today — both in the tools and the dependability. What else can we use?

The GPS is actually only one of several large projects that do the same thing. The Russian system (Glonass) was established around the same time, with satellites launched throughout the 80s and the whole thing aloft by 1995. After the implosion of the Russian economy at the end of the Cold War, maintaining expensive machinery in space wasn’t a priority and it wasn’t until 2000 that Vladimir Putin put it back on the agenda. By last year, 22 satellites were covering all of Russia, and the addition of two more will see Glonass cover the whole world.

Mindful of relying on American or Russian-owned systems, the European Space Agency is building the Galileo system. As the ESA website says, ‘as far back as the 1990s, the European Union saw the need for Europe to have its own global satellite navigation system’. Although it was originally planned for 2012, German news outlet Spiegel reported in July it wasn’t likely to be operational this side of 2018 and that costs had blown out. How we’re to believe EU transport commissioner Jacques Barrot when he said back in April that the system would be working profitably in 2013 is anyone’s guess…

Not to be outdone, China is in the midst of a four-year project to launch its Beidou-2/Compass system, and the Indian Regional Navigational Satellite System (IRNSS) is under development.

So what does that all mean for the rest of us? Simply put, there are more satellites in the sky, which means your GPS device will find the three points of reference it needs to calculate your position quicker. If your iPhone realises it doesn’t have direct line of sight to enough GPS satellites it might look for Glonass or Galileo signals instead.

Of course, such capability depends on the generosity of sovereign governments spending considerable amounts of their taxpayers’ money for their own interests. The US government gave us a unique gift by opening the GPS spec to civilian use, but it only takes one secretive state that isn’t an ally of the market-friendly West to launch a constellation and keep the whole band for itself. Read into it what you will, but China hasn’t released the Compass spec publicly yet.

Of course, with the US economy still limping badly and space exploration more expensive than ever, maybe we shouldn’t even be looking to political leaders. With the mothballing of the last space shuttle only a few months ago, America is officially out of the spaceflight business. NASA has admitted it’s better at mission planning and space research than getting astronauts out there, and a new generation of market-driven spaceflight has sprung up around various tech industry billionaires and starry-eyed dreamers.

Much like we rely on private companies to deliver Internet data to our houses today, should we entrust positioning to industry, where the profit motive can do its work driving costs down? “They tried to do a private/public partnership in Europe on Galileo and that was the way it was going up until two or three years ago,” says UWA’s Dempster. “To be honest I don’t think that business model ever held up. It was always going to have to be publicly funded really.” Or as Will Featherstone, University of WA Professor of Geodesy puts it, “because GPS is free it doesn’t become a commercially defensible idea.”

Both might be right, but with companies like SpaceX and Virgin Galactic set to ferry more goods and people aloft than NASA in the future, leasing your own private GPS might be a possibility. In fact, it’s an idea whose time has come thanks to the vulnerabilities and constraints of space-based positioning, which we’ll look at more below.

Peter Teunissen, a professor with Curtin University’s department of spatial sciences, thinks we should get used to saying GNSS (Global Navigation Satellite System) in preparation for a world where the GPS is just one system among many. “Although GPS has been the sole system for the last 25 years it won’t be in the future,” he says. “The technology of antennas and receivers is an ongoing development, so the integrity and accuracy we get will improve dramatically.” Teunissen also cites the existence of ground-based systems that boost the GPS signal for areas it has trouble reaching, like underwater.

But there’s one more hurdle. The GPS component of a chipset in your device is tuned to the frequency of the GPS signal frequency and wavelength. Glonass, Compass, Galileo and any others will transmit at different frequencies which today’s devices aren’t wired up to receive. If aliens arrive and steal the GPS satellites overnight, few of us will be able to switch over to Glonass as a backup.

If it meant a firmware update you could download over the web it’d be easy, but it’s a hardware issue. Luckily a whole new generation of chips is on the way, with receivers for Glonass and other systems being built in. Expect to hear more about them in the coming year.

Bring the system down

The biggest concern about GPS making headlines in recent months has been security. Earlier this year two US navy ships in San Diego harbour jammed radio signals to simulate a loss of communications during a training exercise. They also took out the air traffic control system at the nearby airport, emergency pagers used to contact doctors at a nearby hospital and the shipping management system for the harbour port. Mobile users all over the city lost signals, ATMs refused withdrawals and chaos reigned for two hours. It took authorities three days to figure out what went wrong.

And that was just an unforseen accident. The technology to disable mobile communications in a given area is already used in entertainment venues for special events. But it’s so cheap and easy to deploy the possibilities for misuse is a little scary. You can go to (Low Prices, High Quality, Have FUN!) and get a portable GPS jammer for AUD$20.25, and if your motives were nefarious maybe you could sit under an airport approach path on a cloudy night when the pilots are relying on instrumentation and turn it on, hoping for the worst.

Maybe we should rethink the push by the aviation industry to turn increasingly to GPS for navigation. “The drive from aviation to get GPS as a landing aid is to get a lot of this ground-based infrastructure packed away because it’s expensive to maintain and keep secure,” says UNSW’s Andrew Dempster.

He adds that GPS jamming — like the whole consumer GPS movement — is also such a new field that law enforcement isn’t really taking much notice of it yet. “At the moment there’s not a lot of responsiveness in the official channels to GPS jamming and there’s not a lot of tools around to do it either.”

The answer might be alternate systems that operate at different frequencies, but it’s a little like the argument that the Macintosh is safer than the Windows PC — a matter of market penetration. “If GPS becomes a problem then you need something else,” Dempster explains, “And we might have to rely on some of these other methods for awhile, but if you jam GPS you can jam them as well, you just jam at a different band.”

There’s also a geopolitical angle to our reliance on GPS — or any other system, for that matter. Any finger hanging over the GPS on/off switch will belong to the US department of defence, an agency that happens to belong to an ally. There’s also a burgeoning industry surrounding GPS that benefits the US economy. But if Iran became the new satnav industry epicentre, would the US keep it going knowing it’s enriching an official enemy? Or imagine the GPS actually belonged to North Korea — would Kim Jong Il release the spec to the US and its allies? Maybe there’s an argument for private ownership of positioning systems after all…

Freedom of choice

Ironically, one of the institutions losing a measure of faith in the GPS is the US military itself. As long ago as 2001, a paper tabled at an Institute of Electrical and Electronics Engineers conference quoted the US Navy as saying it was ‘currently pursuing several approaches to improving the reliability of precision navigation systems, including those that would still permit precision navigation in the event that the Global Positioning System (GPS) is denied or unavailable’.

More recently, innovation and technology blog reported Air Force chief of staff Norton Schwartz’s comments that GPS signals were vulnerable in times of war and could be a security risk while US forces rely so heavily on them. Notwithstanding the fact that the US Air Force has apparently spent a decade dithering over the issue, it makes relying on GPS when our lives depend on it a little scary.

In that light the Russian, European and Chinese systems sound like healthy, old fashioned competition. But it’s not quite the same as choosing from Bigpond, iinet or TPG for your broadband. Each system plots your position and path based on your relationship to other satellites in the network. They all do so through slightly different mathematics, so your device can give you a better result by comparing readings from each system. “The benefit of having the other systems is cross checks that makes the whole system more reliable,” says UWA’s Will Featherstone. But all they give us is more versions of the same thing, with the same vulnerabilities.

One way around the patchy GPS is a dedicated system in a specific area, often for a single purpose. The Sentinel Bushfire Monitoring System is run by Geoscience Australia — a government agency under the minister of Resources, Energy and Tourism. As the name suggests it plots the position of high fire danger areas using temperature readings from NASA satellites by laying the data over dynamically generated maps. With a specific monitoring area (a 2330km swathe of Earth’s surface that includes Australia on each daily flyover), the system could provide a dedicated GPS-style hotspot.

Even more revolutionary is to not go into space at all to deploy your own positioning system. The GPS signal is weak and the input and output completely out of your hands, so LPS – local positioning systems — make sense. As Nunzio Gambale says, “there’s nothing global about positioning in a mall or a mine, it’s inherently a local problem.” Gambale runs Locata, an Australian company that’s leading the way in ground-based positioning. It has dozens of patents and a lot more under application for their system of deploying what the effusive CEO calls ‘locatalites’.

It’s about putting a fleet of very inexpensive GPS transmitters wherever you need them over as small or large an area as you need. The transmission frequencies and wavelengths can be tightly controlled, which mean your network can’t easily be interfered with — the signal from a ground-based unit just on the next hill is literally billions of times louder than the tiny beep from a faraway satellite.

It’s particularly handy in areas where the GPS falls down like indoors or underground. “The first time I walked indoors with a GPS unit and it stopped working I thought ‘what?’,” says Gambale. “We’ve got a completely different angle because we’ve come up with a local positioning system that provides exactly the same function as a GPS.”

One the Locata’s deployments is at a gold mine at Boddington, 115 km south of Perth, one of the unique situations where the technology will excel. “They bought millions of dollars of gear that works when it’s on the surface, but they have a hole four kilometers in diameter going down a kilometre deep and 40 percent of the time they can’t see satellites to give them a position. They have to hire surveyors to go down with string lines and pegs on the ground.”

Local positioning systems work exactly the same as the GPS and Glonass — a simple matter of giving a receiver at least three points of reference (four if you want GPS-accurate time as well) in direct line of sight. But instead of waiting for satellites to soar overhead you can buy as many transmitters as you like and put them exactly where you’ll need them according to the landscape or situation — in Locata’s case they’re small devices the size of a videocassette, which makes it much more scalable than the hundreds of millions of dollars you need to launch a satellite.

And if you still aren’t convinced LPS is a good idea, the US military’s already on the bandwagon. Locata’s biggest deployment is the White Sands missile range in New Mexico, an area 6,500 square kilometers in total (three times the size of the ACT) which will give readings with accuracy of only centimeters, the sort of results you can only get from the military segment of the GPS.

Later when we spoke to Andrew Dempster, he confirmed Gambale’s claim wasn’t just marketing spin. “I’m actually looking out the window at a Locata antenna at the university here. We’ve got a little network of our own that we use for, it’s centimeter-level positioning.”

So don’t fret. We rely on much older technologies than the GPS every day, and even if the worst happens there are plenty of other contenders on their way to keep you covered.